Crystalline solid state materials, such as single-crystal semiconductors, are the basis of the current microelectronics industry. Each single crystalline solid is a periodic structure in space, with a basic repeating unit called the unit cell. Crystalline solids are characterized by a variety of properties, for example, electrical properties such as electrical conductivity or charge mobility, optical properties such as refractive index or speed of photons, thermal properties such as thermal conductivity or thermal expansion, mechanical properties such as stress or strain curves, and chemical properties such as resistance to corrosion or reaction consistency, among others.
Over the past years, theoretical and experimental interests have focussed on controlling various properties of the solid state materials, for example, their optical and/or physical properties. As such, numerous photonic lattice experiments have been carried out to realize photonic bandgap effects at optical wavelength in periodic crystalline solids as a way of obtaining novel photonic properties in such solids. In one photonic lattice experiment, for example, Yablonovitch et al. (E. Yablonovitch. Phys. Rev. Lett., 58, 2059 (1987)) have suggested that the electromagnetic radiation propagating in periodic dielectric structures is similar to the electron waves propagating in a crystal. Yablonovitch et al. realized that setting up a periodic index of refraction pattern in a material can produce a band structure for electromagnetic waves where certain wavelengths can or cannot propagate, producing therefore the electromagnetic wave equivalent of a metal, semiconductor or insulator. If the wavelength is in the order of the dimensions of the crystal lattice, a photonic bandgap (a frequency range where photons are not allowed to propagate) can open up in two or three dimensions and lead to interesting phenomena, such as inhibition of spontaneous emission from an atom that radiates inside the photonic gap or frequency selective transmission and reflection. This way, for example, if a photonic crystal can be constructed to posses a full photonic bandgap, then a photonic insulator is created by artificially controlling the optical properties of the solid.
Other experiments have been carried out to achieve composite crystalline materials with novel physical and chemical properties. For example, the morphology and the local chemistry order of crystalline solid materials, and thus the physical properties of such crystalline materials, have been successfully influenced by creating the so-called “disordered materials.” Disordered materials are defined as compositionally modulated materials characterized by the lack of regular and long-range periodicity, which is typical of crystalline solids. In the disordered materials, atoms or groups of atoms are disbursed through the material so that the constrains of periodicity which characterizes single crystalline materials are removed. As a result, it is now possible to place atoms in three dimensional configurations which were previously prohibited by the lattice constants of the crystalline materials. Accordingly, a whole new spectrum of semiconductor materials having novel physical, chemical and electrical properties has been made available to the semiconductor industry.
One of the limitations inherent in the above-mentioned photonic lattice experiments is the requirement that the dimensions of the lattice must be in the same order of magnitude as the desired band gap wavelength, or in other words, the refractive index variations or discontinuities should have periodicities on the same scale as the wavelength. As the dimensions of the lattice must be in the same order of magnitude as the desired band gap wavelength, the scaling down to the interesting optical and infrared frequencies has posed problems due to the demanded regularity and uniformity of the photonic lattice. In addition, the fabrication of the “disordered materials” is technologically difficult, as it requires non-equilibrium manufacturing techniques to provide a local order and/or morphology different from that achieved with equilibrium techniques. Further, the crystalline cells of the “disordered materials” are relatively thick because of their low absorption and, consequently, they are fragile, expensive and bulky.
Accordingly, there is a need for an improved method of synthesizing new and broad classes of composite materials which have unique photonic, electronic, magnetic, acoustic or superconducting properties that are significantly different from the properties of the materials from which they are formed. There is also a need for fabricating various spatial patterns and/or geometries in solid state materials to improve the photonic, electronic, magnetic, acoustic or superconducting properties of such solid state materials. There is further a need for an improved method of fabricating three-dimensional photonic bandgap structures in a wide variety of solid materials, such as monocrystalline substrates, dielectrics, superconducting materials or magnetic materials, among others. There is also a need for a more advantageous method of generating a wide variety of space group symmetries, with different group symmetries for wavelength regions of interests, in such variety of solid materials.